1. Field of the Invention
The present invention relates generally to an exercise machine and more specifically it relates to an exercise machine cable adjustment system for providing efficient adjustment of the effective length of one or more cables.
2. Description of the Related Art
Any discussion of the related art throughout the specification should in no way be considered as an admission that such related art is widely known or forms part of common general knowledge in the field.
Exercise machines have been in use for many years. One common exercise machine that has enjoyed increasing popularity is the Pilates machine. A conventional Pilates machine generally includes a frame, a track extending across the frame, one or more platforms at the end of the frame, one or more handles extending from the frame, a carriage movably connected to the track, one or more biasing members (e.g. springs, elastic bands) connected between the frame and the carriage to apply a resistance biasing force to the carriage, and a pair of cables with handles connected to the carriage via pulleys. An individual positions their body upon the carriage and then grasps the handles of the cables to pull themselves along with the carriage towards an end of the exercise machine. Moving the carriage away from the end of the frame towards the opposite end of the frame results in the biasing members applying the resistance biasing force which therapeutic or fitness exercises can be effectively performed. U.S. Pat. Nos. 7,803,095 and 8,641,585 to Sebastien Lagree both disclose exemplary exercise machines suitable for Pilates exercises and additional exercises.
One of the core principles for Pilates is control. “Contrology” was Joseph Pilates' preferred name for his method. All Pilates exercises should be performed with authoritative control of the muscles working to lift against gravity as well as the resistance of the springs, thereby controlling the movement of the body and the apparatus.
Another core principle in Pilates is centering. For exercisers to fully control their bodies, they must have a starting place: the center. The center is the focal point of the Pilates Method, and incorporates the major centering muscle groups, such as abdominal and back muscles, gluteal and lower back muscles, hips, and inner thighs. Centering also requires central placement on the apparatus.
Yet another founding principle in Pilates is precision. Precision is essential to correctly practicing the Pilates methods. Without concentration on performing movements with precision each time, and with each exercise repetition on a Pilates apparatus, all the vital benefits of their Pilates routine will be lost.
One key advantage of the Pilates method over other forms of exercise is that throughout an entire session, and more importantly, throughout the lifelong practicing of Pilates, exercisers perform smooth, flowing exercise forms, and do not experience the damaging effects of exercises such as running that subjects the exerciser to continual spinal and joint impact, or weight power lifting that often strains and injures joints, muscles and connective tissue. In some instances, contemporary Pilates apparatuses incorporate various accessories that allow for the performance of exercises that cannot be reasonably performed on traditional apparatuses, for instance foot bars, handles, and cable and pulley systems. Although many contemporary accessories were not components of Joseph Pilates original apparatuses nearly 100 years ago, the addition of such accessories must remain true to the design principles that allow the Pilates method to be performed with control, centering, and precision.
Therefore, contemporary accessories that are incorporated into a Pilates apparatus must not only support the tenets of the Pilates method, but must also maximize user safety by minimizing injury to joints, muscles and connective tissue. In some instances, cables and pulleys are arranged on a Pilates apparatus to allow for the performance of pulling exercises. Handles attached to cables allow exercisers to use their arms to overcome the spring resistance force, thereby exercising shoulders, upper back, chest muscles, and arm muscles. Foot straps attached to cables allow exercisers to overcome the spring resistance through leg movements, for instance, leg adductor and abductor exercises that exercise the inner and outer thigh muscles.
Cables and pulleys are nearly always arranged in pairs such that an exerciser can grasp one handle in each hand, and work the arms simultaneously. By pulling on the handles, the exerciser can start, perform, and finish the exercises of the left and right arms in mirror fashion.
There are many factors unforeseen and unpredictable that cause a pair of pull cables on a Pilates apparatus to be unequal lengths. More specifically, a pull cable of a Pilates apparatus is preferably described as a pull cable assembly, comprising a first connector affixed to a first end of the cable allowing the cable to be attached to the Pilates apparatus, a length of cable, a second connector affixed to a second end of the cable, and a gripping handle or foot strap attached to the second connector.
In some cases, connectors simply break, and the Pilates instructor will find other connectors within the facility, and conduct a fast repair. For instance, a large oblong carabineer connector may be replaced with a short hook in order to return the apparatus to operational status.
In other cases, prolonged use of the pull cables will cause the cables to stretch in length, or fray where the cables pass through pulleys. Cables in disrepair are replaced with new cables, and often, only the most badly damaged cable of a pair of cables is replaced. After replacement, the new cable is not stretched to the same length as the older cable, causing the cables to be different lengths.
In yet other practical circumstances, a handle attached to one cable may break or come into disrepair. Over time, Pilates studios amass an inventory of spare parts scavenged from other apparatuses, and will find an acceptable replacement handle, although not of original equipment design. There is no dimensional standard for pull cable handles, therefore there is high likelihood that the replacement handle has a pull length different from the original equipment handle.
Still further, even if purchased from the original equipment manufacturer at a later date, subcontracted manufacturers' tolerances, engineering changes for cost reduction or reliability improvements, or material changes typically mean that replacement parts are not exact replicas of the original equipment, usually resulting in a total pull cable assembly length that is different from the pull cables installed on the Pilates apparatus.
Each and every one of these disadvantages to pull cable assemblies of a Pilates apparatus are well known in the industry, and each can result in different functional lengths of the two pull cables on one Pilates apparatus.
In each of these cases where exercisers are performing Pilates exercises on an apparatus with different length cables, exercisers are forced into positions that violate each of the foundational Pilates principles of control, centering and precision. Even a slightly modified position that the body naturally assumes to adjust to the different length cables subjects the muscles, joints and connective tissue on one side of the body to more force than the opposite side of the body. The additional and unbalanced force can cause injury to the exerciser.
Unequal length pull cable assemblies creates forces against the spring resistance that are biased towards one side of the body rather than balancing the forces equally, or cause the left and right hands, or left and fight feet to be positioned at different locations when the left and right sides are exerting equal forces against the resistance.
Further, use of pull cables of unequal lengths that bias forces unequally on the body can result injury. Still further, applying unequal forces on the outside corners of the slidable carriage of a Pilates apparatus can cause skewing of the carriage on the parallel rails, thereby causing accelerated or excessive wear on rollers and rails.
Those skilled in the art will immediately appreciate the need for, and the significant commercial value of a novel an improved cable and pulley system of a Pilates apparatuses that incorporate a fast, precise method of evening cable lengths such that the user can remain centered and in precise control throughout an exercise on the apparatus, and further ensures that the resistance force is balanced evenly between the first and left sides of the body.